Heretofore, in processes for the production of semiconductor device, for example, IC or LSI, microfabrication has been conducted by means of lithography using a photoresist composition. In recent years, as the degree of integration in integrated circuits increases, it has been requested to form an ultrafine pattern in the submicron region or the quarter micron region. With such a trend, an exposure wavelength tends to become shorter, for instance, from g-line to i-line and further to a KrF excimer laser beam. Moreover, the development of lithography using an electron beam, an X ray or EUV light also proceeds at present in addition to the use of an excimer laser beam.
The lithography using an electron beam, an X ray or EUV light as the light source is positioned as the pattern formation technique of next generation or next-next generation, and a resist composition having high sensitivity and high resolution is demanded.
In particular, for reducing wafer processing time, increase in the sensitivity is a very important problem. However, when the increase in the sensitivity is tried to pursue, pattern profile, line width roughness (LWR) or resolution represented by limiting resolution line width is deteriorated, and development of a resist composition satisfying all of these properties at the same time is strongly demanded.
The high sensitivity is in a trade-off relationship with the high resolution, line width roughness (LWR) or good pattern profile, and it is important how to satisfy all of these properties at the same time.
On the other hand, for example, in Patent Document 1, from the standpoint of preventing the generation of outgas for avoiding exposure device contamination it is described to provide a top coat layer on a resist film.
Also, in Patent Document 2, it is described to suppress development defects by incorporating a resin having an acid group into a top coat layer.
Further, in recent years, the need for forming a fine pattern is drastically increased, and in response thereto, further performance improvements in high sensitivity, high resolution, line width roughness (LWR) and good pattern profile have been requested in the formation of fine pattern having a line width of 60 nm or less.